The Secret War in El Paso: Mexico Revolutionary Intrigue, 1906–1920

Professors emeritus from New Mexico State University in Las Cruces, Charles Harris and Louis Sadler are (or should be) familiar names to anyone studying pre-1940s intelligence history. They have published several excellent studies, including The Archaeologist Was a Spy: Sylvanus G. Morley and the Office of Naval Intelligence (2003) and The Border and the Revolution: Clandestine Activities of the Mexican Revolution 1910-1920 (1988). The two began work on Secret War several decades ago as a history of gunrunning in El Paso during the Mexican Revolution. However, as such studies often do, this one expanded as they discovered that gunrunning was only part of a much larger picture — an intelligence battle between US agencies and a kaleidoscope of contending Mexican factions.

Harris and Sadler’s work breaks interesting new ground because they have carefully sifted through records not previously explored in great depth. They combed declassified records from the FBI, Naval Intelligence, the Department of Justice, the United States Secret Service, and the Mexican archives — not always an easy task. Together they form an elaborate intelligence puzzle. Their work shows how a careful reconstruction from such disparate records can illuminate a long-forgotten piece of US intelligence history.

Like good historians, or intelligence officers, Harris and Sadler let the evidence lead them to the story. An example is the frequently ignored meeting of President William Howard Taft and Mexican President Porfirio Díaz in El Paso in 1910, when primitive intelligence-sharing prevented a major diplomatic crisis. At the time of the meeting, Díaz was facing growing opposition, and informants had reported assassination plots against him. Despite the dubious provenance of many of the reports, a heavier presence of Mexican and US troops at the meeting than had been originally planned as well as a “private, ‘off-the-books’ security force” recruited by one of Taft’s friends prevented an attempt on Díaz’s life.(15) Had Díaz been assassinated on US soil, the ensuing crisis could have propelled the United States into much more involvement in Mexican affairs.

The intelligence sharing established a precedent that would be repeated throughout the decade. After Mexican reformer Francisco Madero replaced Díaz in 1911, US officials took an even more active role in cooperating with the Mexican government to obstruct revolutionary activity on US soil. The “most striking aspect,” the authors note, “was the degree to which US and Mexican intelligence agencies cooperated.”(377) While liaison cooperation never entirely stopped illegal arms shipments across the border, even the partially effective embargo made it more difficult — and more expensive — to buy arms in the United States for use in Mexico.

Because neither country had experienced intelligence officers in today’s sense of the word, the role of intelligence was largely a contest between amateurs. Harris and Sadler cite the example of the Thiel Detective Service, an American company operating in El Paso. Hired by Madero’s government to report on counter-revolutionaries based in the city, Thiel’s agents passed copies of their reports to US officials without the knowledge of Madero's government. (82) Such multiple allegiances were common, as neither country had established protocols to vet sources. In addition, double agents were often uncovered by accident or were betrayed by other double agents trying to earn a reward.

A notable amateur was Felix Sommerfeld, an agent who worked for several Mexican factions, switching loyalties as conditions changed. A German who had been decorated by the Kaiser’s government for his actions during the Chinese Boxer Rebellion in 1900, Sommerfeld had by 1912 become a mining engineer with experience in Mexico and the United States — he also served as a reporter for the Associated Press. The authors observe that “Sommerfeld would move through the Mexican Revolution like a wraith…,” (76) attaching himself to Madero, then to anti-Huerta Constitutionalists, then to revolutionary Venustiano Carranza, and, finally, Pancho Villa. All the while he cooperated with the United States when it served the interests of the faction he was backing.

What we would call HUMINT dominated the type of information gathered by agents on each side, although there were a few attempts at using emerging technologies to acquire COMINT. Harris and Sadler note that US officials tried to plant recording devices such as Dictaphones in hotel rooms. The information received was unreliable and sometimes deliberately intended for Washington’s ears by factions hoping to win official favor. The only topic Harris and Sadler failed to discuss in sufficient detail, in my judgment, is the role of third-party actors, in particular the Europeans. They mention German actions in the border area after the United States entered the Great War in April 1917, but they could have covered what the Germans (and British) were doing in the border region during the rest of the decade. Maybe there wasn’t much, but the accounts of activity elsewhere as covered by Frederick Katz in The Secret War in Mexico (1983) and Barbara Tuchman in The Zimmerman Telegram, (1958) suggest otherwise.

Covering their topic in largely chronological order, Harris and Sadler introduce an enormous roster of actors. A who’s who would have been helpful, as I occasionally found myself referring to the index to refresh my memory—though I think the index is too short and probably inadequate to meet the needs of follow-on researchers. The story flows smoothly, however, and the authors write with wit and humor. Their bibliography is impressive, including the major works on the United States and the Mexican Revolution. The illustrations include numerous unique photos. In sum, the book is well-done and should be read by anyone interested in the Mexican Revolution or in American intelligence operations in the years before the development of formal intelligence processes.

All statements of fact, opinion, or analysis expressed in this article are those of the author. Nothing in the article should be construed as asserting or implying US government endorsement of its factual statements and interpretations.